Heisenberg was uncertain on principle
He wasn’t sure if Hitler was invincible.
He went to see Bohr
During the war,
But we’re not terribly certain what for.
Heisenberg’s world was certainly fragmented.
His uncertainly thought-out ethics were splintered
If he chose not to see
What went on in Germany
I wonder what uncertainty means?
He couldn’t deny with certainty.
Concentration camps were not a rarity.
But he trembled unsure
Right through the War,
So maybe that’s what uncertainty’s for.
I guess uncertainty was not as bad
As the total denial some of us had.
Painful to tolerate,
And on nuclear bombs to concentrate.
Whilst most certainly wanting Bohr for a mate
How my heart sings 
This was an extraordinary period of history. We should remember that nuclear fission was discovered by the chemist, Otto Hahn, in Germany in 1938. Fortunately for us all, Hahn was an opponent of National Socialism and had already helped a Jewish colleague, Lisa Meitner, to escape from Germany. He wrote to her in Stockholm about his findings but, crucially, did not tell the physicists in his own institute. As a result, the theory of nuclear fission was worked out in Birmingham, rather than in Germany.
Einstein wrote that Hahn was “one of the very few who stood upright and did the best he could in these years of evil”
That’s wonderful.I didn’t know.Thank you so much for telling us this important and very moving history.
Yes, it is a pity that the veil of secrecy, which descended on all nuclear matters after the war, prevented some heroic actions from being recognised at the time.
Yes,I was saying that to some former colleaugues about the Bletchley people like Alan Turing